As is known, doors of motor vehicles generally comprise a frame-like top portion, which defines a window opening closed by a mobile window, when the latter is raised, and a bottom box-type portion formed by an outer panel and by an inner panel, which are joined at one end by a head edge and together define a compartment, in which there are commonly housed the window, when the latter is lowered, and the various components fixed to the panels themselves, among which, for example, the lock, the key unit, the internal and external handles, the various members for connection between the aforesaid components, and the window-regulator device.
Conveniently, the components mentioned above are inserted in the compartment of the door through one or more openings made in the inner panel and are variously assembled together and fixed to the panels themselves.
Said operations are relatively long and problematical and hence entail long stoppage times of the doors in various stations along the assembly line, with relatively high costs linked thereto.
There is therefore felt, in the sector, the need to create pre-assembled functional units, which include some of the aforementioned components so as to enable a drastic reduction in the times of assembly of the doors.
Parallel to this, there is an increasingly widespread use of electrically operated actuators for controlling window-regulator devices and for providing the main functions associated to modern locks.
In particular, as is known, a lock for a motor vehicle typically comprises a closing mechanism, designed to couple in a releasable way with a fixed lock striker for bringing about closing of the door, and an actuation assembly, which is designed to control release of the closing mechanism from the lock striker and can be connected to the manual-control elements associated to the door of the motor vehicle, such as, for example, the internal and external handles and the key unit.
More precisely, the actuation assembly in general comprises an internal control lever connected to the internal handle of the door, an external control lever connected to the external handle of the door, and a safety linkage, which can be actuated by means of a key from the outside of the motor vehicle and by means of a knob and/or the internal handle to disable or enable opening of the door by means of the external handle so rendering the external control lever non-effective or effective, respectively (external safety function activated or deactivated).
Traditional locks are moreover generally provided with a linkage for disabling/enabling opening from inside the motor vehicle (internal safety function or dead-lock function activated or deactivated).
The aforementioned safety functions and the functions for opening and closing lock are ever more frequently obtained with the aid of respective electrically operated actuators, which are, in turn, controlled via microswitches and/or signalling devices.
It is therefore evident that, as the number of actuators used increases, this gives rise to an excessive complication of the corresponding locks both from the standpoint of the electronic control and from the mechanical standpoint, with an increase in the overall costs, dimensions, weight, and with a possible onset of problems of reliability. These drawbacks tend to be further amplified in the case where pre-assembled units are provided, which include not only the locks of the type described above but also other electrically controlled components.